Research on the monitoring system for induced voltage and ground current of 27.5 kV cable sheath in railways

Purpose–The purpose of this study is to address the deficiency in safety monitoring technology for 27.5 kV high-voltage cables within the railway traction power supply by analyzing the grounding methods employed in high-speed railways and developing an effective monitoring solution.Design/methodology/approach–Through establishing a mathematical model of induced potential in the cable sheath and analyzing its influencing factors,the principle of grounding current monitoring is proposed.Furthermore,the accuracy of data collection and alarm function of the monitoring equipment were verified through laboratory simulation experiments.Finally,through practical application in the traction substation of the railway bureau on site,a large amount of data were collected to verify the stability and reliability of the monitoring system in actual environments.Findings–The experimental results show that the designed monitoring system can effectively monitor the grounding current of high-voltage cables and respond promptly to changes in cable insulation status.The system performs excellently in terms of data collection accuracy,real-time performance and reliability of alarm functions.In addition,the on-site trial results further confirm the accuracy and reliability of the monitoring system in practical applications,providing strong technical support for the safe operation of highspeed railway traction power supply systems.Originality/value–This study innovatively develops a 27.5kV high-voltage cable grounding current monitoring system,which provides a new technical means for evaluating the insulation status of cables by accurately measuring the grounding current.The design,experimental verification and application of this system in high-speed railway traction power supply systems have demonstrated significant academic value and practical significance,contributing innovative solutions to the field of railway power supply safety monitoring.

Controlling Airy-Bessel Light Bullets in an Optically Induced Potential

We investigate numerically the curious evolution of self-decelerating Airy-Bessel light bullets carrying different topological charges(TC), launched in the three-dimensional(3 D) Schr?dinger equation with an induced parabolic potential. We present their spatiotemporal profile during propagation. In our paper, the number of TC, the modulation depth, and the induced potential are considered simultaneously. The propagation properties of light bullets result from a combination of these effects. Our scheme is distinctly different from the linear light bullets in free space, in which the localized wave packets propagate in a self-consistent trapping potential.

Differential Proteomics Reveals the Potential Injury Mechanism Induced by Heavy Ion Radiation in Mice Ovaries

In the present study, we used a proteomics approach based on a two-dimensional electrophoresis （2-DE） reference map to investigate protein expression in the ovarian tissues of pubertal Swiss-Webster mice subjected to carbon ion radiation （CIR）. Among the identified proteins, ubiquitin carboxy-terminal hydrolase L1 （UCH-L1） is associated with the cell cycle[1] and that it influences proliferation in ovarian tissues. We analyzed the expression of UCH-L1 and the proliferation marker proliferation cell nuclear antigen （PCNA） following CIR using immunoblotting and immunofluorescence. The proteomics and biochemical results provide insight into the underlying mechanisms of CIR toxicity in ovarian tissues.

Coherent charge transport in ferromagnet/semiconductor nanowire/ferromagnet double barrier junctions with the interplay of Rashba spin-orbit coupling, induced superconducting pair potential,and external magnetic field

By solving the Bogoliubov-de Gennes equation, the influence of the interplay of Rashba spin-orbit coupling, induced superconducting pair potential, and external magnetic field on the spin-polarized coherent charge transport in ferromagnet/semiconductor nanowire/ferromagnet double barrier junctions is investigated based on the Blonder-Tinkham-Klapwijk theory. The coherence effect is characterized by the strong oscillations of the charge conductance as a function of the bias voltage or the thickness of the semiconductor nanowire, resulting from the quantum interference of incoming and outgoing quasiparticles in the nanowire. Such oscillations can be effectively modulated by varying the strength of the Rashba spin-orbit coupling, the thickness of the nanowire, or the strength of the external magnetic field. It is also shown that two different types of zero-bias conductance peaks may occur under some particular conditions, which have some different characteristics and may be due to different mechanisms.

Changes of evoked potential in different hippocampal regions induced by electrostimulation at medial mamillary nucleus of rats

BACKGROUND： Morphological data have shown that the most important afferent fibers of papillary body come from hippocampal structure.OBJECTIVE： To observe the changes of evoked potential in hippocampus and the significance after electrostimulation at medial mamillary nucleus. DESIGN： An observational control experiment.SETTING： Department of Physiology, Shenyang Medical College.MATERIALS ： Twenty-three male or female Wistar rats, 3-4 months old, weighing 270-350 g, were provided by bhe animal room of Shenyang Medical College [the license number was scxk（Liao）2003-0016]. METHODS： The Wistar rats were anaesthetized by intraperintoneal injection of 20% urethane （1 g/kg）, tracheal intubation was also given. The self-made double-pole metal stimulating electrode with the point diameter of 1 mm was inserted into medial mamillary nucleus, the wanted hippocampal guidance spot was found within the rang of the hippocampal region at the same side of tee mamillary body range （CA1-CA4）, inserted with same-core guidance electrode, a sole square-wave stimulation of wave wide 0.2 ms stimulated with electrodes at the applied intensity of 7-9 V, the evoked potential was induced through guidance electrodes, and then input to the ATAC-350 data-processing machine for memory showing wave processing, the memory recorded wave recording graph was separately drawn up by the X-Y recording instrument to observe the latency, time procedure and amplitude of the evoked potential in each hippocampal region of the rats and calculate the percentage of the evoked potential in each hippocampal region. Totally 78 guidance spots in hippocampus were recorded, including 30 positive reaction spots and 48 negative ones. MAIN OUTCOME MEASURES： ① Latency, time procedure and amplitude of the evoked potentials in each hippocampal region of rats; ②percentage of the evoked potentials in each hippocampal region; ③ the wave shapes of the evoked potentials in each hippocampal region from different arrangement in the same positive reaction spot. RESULTS ：① Of the 30 recorded positive reactions, 9 positive spots fused into the stimulated false marks because of the short latency. The analysis of variance showed that the latency had significant difference （P 〈 0.05）, time procedure had highly significant difference （P 〈 0.01 ）, but there was no significant difference in the amplitude （P 〉 0.05） among the hippampal regions.② Among the 30 positive spots, the percentage of evoked potential in the hippocampal regions were 34.5% for CA1, 2.0% for CA2, 24.1% for CA3 and 22.4% for CA4. ③ In different levels of the same positive spot, different changes of the evoked potential wave shapes could be observed, and the most obvious change was that of positive wave amplitude. At different positive spots, evoked potentials of positive phase, negative and the double-phase could be observed. CONCLUSION： There are nerve associations between mamillary body and hippocampus, afferent fibers of mamillary body come from hippocampal CA1 region are a little more.

Effects of Thermal Lattice Vibration on the Effective Potential of Weak-Coupling Bipolaron in a Quantum Dot

Based on the Huybrechts' linear-combination operator,effects of thermal lattice vibration on the effective potential of weak-coupling bipolaron in semiconductor quantum dots are studied by using the LLP variational method and quantum statistical theory.The results show that the absolute value of the induced potential of the bipolaron increases with increasing the electron-phonon coupling strength,but decreases with increasing the temperature and the distance of electrons,respectively;the absolute value of the effective potential increases with increasing the radius of the quantum dot,electron-phonon coupling strength and the distance of electrons,respectively,but decreases with increasing the temperature;the temperature and electron-phonon interaction have the important influence on the formation and state properties of the bipolaron:the bipolarons in the bound state are closer and more stable when the electron-phonon coupling strength is larger or the temperature is lower;the confinement potential and coulomb repulsive potential between electrons are unfavorable to the formation of bipolarons in the bound state.

Relevance and therapeutic potential of Cyp A targeting to block apoptosis inducing factor-mediated neuronal cell death

Programmed cell death （PCD） signaling pathways are import- ant contributors to acute neurological insults such as hypox- ic-ischemic brain damage, traumatic brain injury, stroke etc. The pathogenesis of all these diseases is closely linked with ab- erration of apoptotic cell death pathways. Mitochondria play a crucial role during PCD, acting as both sensors of death signals, and as initiators of biochemical path- ways, which cause cell death （Bras et al., 2005）. Cytochrome c was the firstly identified apoptogenic factor released from mitochondria into the cytosol, where it induces apoptosome formation through the activation of caspases. Other proteins, such as apoptosis inducing factor （AIF）, have been subsequently identified as mitochondrial released factors. AIF contributes to apoptotic nuclear DNA damage （Bras et al., 2005）. in a caspase-independent way

Electrical properties of carbon nanotubes in flowing vapor

Electric potentials were generated from carbon nanotubes immersed in flowing vapors. The nanomaterials used in this study were multiwall carbon nanotubes（MWCNTs） and silver nanopowders. These nanomaterials were dispersed and densely packed on a substrate and immersed in flowing vapors generated from solution such as water, ethanol and KCI. The potentials generated from these samples were measured by a voltmeter. Experimental results showed that the electric potentials were produced at the surface of the MWCNT samlpes, and strongly dependent on the pretreatment of MWCNT and properties of the flowing vapors. The mechanism of vapor-flow induced potentials may be ascribed to ions in the flowing vapors. This property of MWCNTs can advantage their application to nanoscale sensors, detectors and power cells.

CHANGES IN THE ENDOCOCHLEAR POTENTIAL AND COCHLEAR BLOOD FLOW INDUCED BY ATP INFUSION AND ARTERIAL OCCLUSION

To assess the relationship between cochlear blood flow (CBF) and auditory function, a procedure of intravital microscopy for observations of the lateral wall vessels of the cochlea coupled with the simultaneous measurement of the endocochlear potential (EP) was established in guinea pigs with gradual ischemia of the cochlea. It was found that occlusions of both common carotid arteries and one of the vertebral arteries produced a minor reduction in CBF with no significant alteration in the EP. When intravenous infusion of ATP induced sharp and severe decreases in CBF, the EP varied only slightly from the baseline in some animals while there were no alteration in others. Furthermore, ATP infusions combined with arterial occlusions caused even more severe declines in CBF and a moderate decrease in the EP. The results indicate that not only does the CBF satisfy the basic needs of the processes of cochlear function, but also has a regulatory mechanism to ensure the normal function of the cochlea in the ischemia condition. It was also found that the changes in the stria vascularis vessels induced by decreases in blood pressure (BP) and heart rates were more severe than those of the spiral ligament vessels. This phenomenon indicated that the stria vascularis vessels were more sensitive to decreases of BP and heart rates.

Polarization effects and tests for crystalline silicon solar cells

We try to find a fast and simple potential induced degradation effect （PID） test procedure for crystalline silicon solar cells. With sodium chloride （NaC1） solution as Na＋ source, PVB as lamination material, we can carry out the test in 1 h. Solar cells with newly developed PID resistance process were also tested. The increase of reverse current of solar cell can be considered a key standard to determine if the solar cell was prone to PID. Moreover, it showed that the increase of reverse current for the PID resistance solar cell was less than 2. In addition, the test results of the solar cells fitted very well with that of the modules by standard procedure.